net/mlx5: fix inconsistent link status

Querying the link status can end up being in an inconsistent state,
like the port is reporting speed although it is down.

For this case another query is scheduled.

A race condition can occur between the scheduled query and link
status interrupt handlers.

When the scheduled query by-pass interrupt handlers, the link status
will be stuck in an inconsistent state.

This patch addresses the race condition by not blocking link status
queries in case delayed query is used.

Fixes: 198a3c339a ("mlx5: handle link status interrupts")
Cc: stable@dpdk.org

Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
This commit is contained in:
Shahaf Shuler 2017-01-31 15:13:38 +02:00 committed by Ferruh Yigit
parent 511a4c74b8
commit a9f2fbc42f

View File

@ -1125,7 +1125,7 @@ static int
priv_dev_link_status_handler(struct priv *priv, struct rte_eth_dev *dev)
{
struct ibv_async_event event;
int port_change = 0;
struct rte_eth_link *link = &dev->data->dev_link;
int ret = 0;
/* Read all message and acknowledge them. */
@ -1133,29 +1133,24 @@ priv_dev_link_status_handler(struct priv *priv, struct rte_eth_dev *dev)
if (ibv_get_async_event(priv->ctx, &event))
break;
if (event.event_type == IBV_EVENT_PORT_ACTIVE ||
event.event_type == IBV_EVENT_PORT_ERR)
port_change = 1;
else
if (event.event_type != IBV_EVENT_PORT_ACTIVE &&
event.event_type != IBV_EVENT_PORT_ERR)
DEBUG("event type %d on port %d not handled",
event.event_type, event.element.port_num);
ibv_ack_async_event(&event);
}
if (port_change ^ priv->pending_alarm) {
struct rte_eth_link *link = &dev->data->dev_link;
priv->pending_alarm = 0;
mlx5_link_update(dev, 0);
if (((link->link_speed == 0) && link->link_status) ||
((link->link_speed != 0) && !link->link_status)) {
mlx5_link_update(dev, 0);
if (((link->link_speed == 0) && link->link_status) ||
((link->link_speed != 0) && !link->link_status)) {
if (!priv->pending_alarm) {
/* Inconsistent status, check again later. */
priv->pending_alarm = 1;
rte_eal_alarm_set(MLX5_ALARM_TIMEOUT_US,
mlx5_dev_link_status_handler,
dev);
} else
ret = 1;
}
} else {
ret = 1;
}
return ret;
}
@ -1175,6 +1170,7 @@ mlx5_dev_link_status_handler(void *arg)
priv_lock(priv);
assert(priv->pending_alarm == 1);
priv->pending_alarm = 0;
ret = priv_dev_link_status_handler(priv, dev);
priv_unlock(priv);
if (ret)